Support use of custom app root with system config in CLI commands (#1600)

## Type of Change
- [x] Bug fix

## Motivation and Context
Many CLI commands need to reference the system configurations for
`container`. Previously, CLI commands would try to load the system
configurations from the default application root location, regardless of
if `container` had been started with a custom application root location.
This PR fixes that issue by having each CLI command ping the APIServer's
health check service to get the correct app root path.

Closes https://github.com/apple/container/issues/1576

## Testing
- [x] Tested locally

Signed-off-by: Kathryn Baldauf <k_baldauf@apple.com>

Sources/ContainerCommands/Container/ContainerCreate.swift

@@ -56,7 +56,7 @@ extension Application {
         var arguments: [String] = []
 
         public func run() async throws {
-            let containerSystemConfig: ContainerSystemConfig = try await ConfigurationLoader.load()
+            let containerSystemConfig: ContainerSystemConfig = try await Application.loadContainerSystemConfig()
             let progressConfig = try ProgressConfig(
                 showTasks: true,
                 showItems: true,

Sources/ContainerCommands/Container/ContainerRun.swift

@@ -63,7 +63,7 @@ extension Application {
         var arguments: [String] = []
 
         public func run() async throws {
-            let containerSystemConfig: ContainerSystemConfig = try await ConfigurationLoader.load()
+            let containerSystemConfig: ContainerSystemConfig = try await Application.loadContainerSystemConfig()
             var exitCode: Int32 = 127
             let id = Utility.createContainerID(name: self.managementFlags.name)